Diff repair in a W109

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helgathe109
C Class
Posts: 33
Joined: Mon 09 Nov, 2015 9:51 am
Model you own: w109

Diff repair in a W109

Post by helgathe109 » Fri 24 Feb, 2017 9:30 am

Hey all,

My stubborn diff leak has returned. I'd previously reduced the amount of diff oil that was leaking by replacing the driveshaft boot with one of those split ones. Despite the mixed feedback on the split boots, it's actually still doing the job quite well (for the 1000km or less that it will get driven each year). Now that the diff isn't leaking from the boot (or so it seems), there is still diff oil coming out from somewhere. It's difficult to pin point where it is coming from, as it's pretty tight under there on jack stands, but there appears to be oil infront of the boot... so I'm thinking I'll have to drop the diff and take it somewhere to get fixed.

The local classic MB place in Sydney has quoted me $2k to replace the boot and pinion seal, if I drop the diff and take it to them. If they have to remove/replace, then add another 800-1000. I'm thinking this is typical "Classic MB" pricing, so I'm planning on dropping the diff and taking it to a diff specialist closer to home.

As the diff specialist probably doesn't have a stock of classic MB parts on hand, what parts should I order to deliver with the diff?

I've pulled the below list of parts off the web, but not sure on what would be necessary and what I could leave out...

Differential Pinion Seal 004-997-56-46-MBZ
Center Support Cushion for Drive Shaft 108-413-01-12-M22
Flex Disc Kit 126-410-02-15-MBZ
Center Support Bearing 008-981-43-25-MBZ
Driveshaft Boot 202-411-04-97-MBZ
Drive Shaft Centering Bushing 115-410-00-32-MBZ

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Bartman4800
300 SLR
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Joined: Fri 10 Oct, 2008 12:10 am
Model you own: w111
Location: Perth WA

Re: Diff repair in a W109

Post by Bartman4800 » Fri 24 Feb, 2017 11:12 am

These 2 items are for the centre bearing in the propshaft. They only have to be replaced if the centre bearing is noisy or the cushion is flogged out.
You will remove the propshaft to be able to remove the rear axle.

DCenter Support Cushion for Drive Shaft 108-413-01-12-M22
Center Support Bearing 008-981-43-25-MBZ rive Shaft Centering Bushing 115-410-00-32-MBZ

The flex disc is good to replace if it has some cracks in it.

Flex Disc Kit 126-410-02-15-MBZ

The problem with the removing the pinion to remove the seal, is that it will have to be adjusted to the correct position again. This is specialist work.
To replace the boot, the swing arm has to be removed.
This can reveal wear on the swing arm bushes and pin, which might have to be replaced.

Better to bring this to someone who has done this before, not an ordinary diff specialist.

Also, the centre mount above the diff needs to be inspected and replaced if suspect. You can do this yourself once the rear axle is removed.

I reckon all bushes are available from MBspares.


Bart
1963 220 Sb Sedan "Kermit" (Australian Assembly)
1960 220 Sb Sedan "Zum Schlachten" (Early German Assembly, with a torsion bar spring for the bonnet) - Stored in Country WA
1981 Subaru Brumby 1.8 with Weber and 5-speed box "little utie" - Sold to another enthusiast!
2006 Ford Focus "missus car"
2002 VW Passat V6 30V Station Wagon (my new commuter bus)

helgathe109
C Class
Posts: 33
Joined: Mon 09 Nov, 2015 9:51 am
Model you own: w109

Re: Diff repair in a W109

Post by helgathe109 » Wed 08 Mar, 2017 5:41 pm

Does anyone know if a W124 diff will bolt straight into a W109?

I found this old post from mercmad when googling... now I'm interested..
Mercmad wrote:here is what i reckon to to be the best idea. it's a W124 diff lifted up as complete unit. it's harder here,but overseas you can get difs from things like 430E's which will take anything you can throw at them and the unit fits easily. The one in the pic has air suspension too.
W111 W124 W201 diff mount.jpg
W111 W124 W201 diff mount.jpg

CraigB
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Re: Diff repair in a W109

Post by CraigB » Wed 08 Mar, 2017 8:47 pm

Certainly won't bolt straight in - completely different set up ie. not a swing axle - but anything is possible with enough modifications.
Craig Baulderstone
Lurch
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Bartman4800
300 SLR
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Joined: Fri 10 Oct, 2008 12:10 am
Model you own: w111
Location: Perth WA

Re: Diff repair in a W109

Post by Bartman4800 » Thu 09 Mar, 2017 1:25 pm

helgathe109 wrote:Does anyone know if a W124 diff will bolt straight into a W109?

I found this old post from mercmad when googling... now I'm interested..
Mercmad wrote:here is what i reckon to to be the best idea. it's a W124 diff lifted up as complete unit. it's harder here,but overseas you can get difs from things like 430E's which will take anything you can throw at them and the unit fits easily. The one in the pic has air suspension too.
W111 W124 W201 diff mount.jpg
W111 W124 W201 diff mount.jpg
Have you ever looked underneath either of these cars?

It can be made to fit, but you can fit the Eiffel tower on top of Trump Tower if you try hard enough.... :laughing6:

Bart
1963 220 Sb Sedan "Kermit" (Australian Assembly)
1960 220 Sb Sedan "Zum Schlachten" (Early German Assembly, with a torsion bar spring for the bonnet) - Stored in Country WA
1981 Subaru Brumby 1.8 with Weber and 5-speed box "little utie" - Sold to another enthusiast!
2006 Ford Focus "missus car"
2002 VW Passat V6 30V Station Wagon (my new commuter bus)

helgathe109
C Class
Posts: 33
Joined: Mon 09 Nov, 2015 9:51 am
Model you own: w109

Re: Diff repair in a W109

Post by helgathe109 » Thu 09 Mar, 2017 2:11 pm

Bartman4800 wrote:
helgathe109 wrote:Does anyone know if a W124 diff will bolt straight into a W109?

I found this old post from mercmad when googling... now I'm interested..
Mercmad wrote:here is what i reckon to to be the best idea. it's a W124 diff lifted up as complete unit. it's harder here,but overseas you can get difs from things like 430E's which will take anything you can throw at them and the unit fits easily. The one in the pic has air suspension too.
W111 W124 W201 diff mount.jpg
W111 W124 W201 diff mount.jpg
Have you ever looked underneath either of these cars?

It can be made to fit, but you can fit the Eiffel tower on top of Trump Tower if you try hard enough.... :laughing6:

Bart
If you're talking to me, then yes... have spent almost every weekend for the last 2 years under it. I was more curious as to whether the W124 diff would be an easy fit given mercmad's comment above (which makes it seem as so). If it's just the same amount of work as any custom diff swap, then there's a whole heap of other options I'd rather go with..

ibast
E Class
Posts: 72
Joined: Wed 16 Mar, 2016 7:18 pm
Model you own: w108
Location: Sydney

Re: Diff repair in a W109

Post by ibast » Tue 18 Apr, 2017 4:26 pm

He's not talking about the diff only, but rather the entire rear suspension.

So unless you are willing to weld some new members in, get all your alignment right, get it engineered etc, then the answer is "no".

The diff rebuild you should be able to do most of it yourself. Bartman is right, in that the meshing of the pinion is critical. You have two choices there. You can either take that bit of the assemble to a diff specialist or you can do some research on how to do it yourself.

$2k is ridiculous if you are having to remove the diff yourself.

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